Multiple arch dam



I July 12, 1932. R. w. VAN NORDEN ULTIPLE ARCH DAM Filed Aug. 8, 1927 2 SheetS-ShBGt l V417 J/(/ A TTORNEK I/VVE/VTO m July 12, 1932.

R. w. VAN NORDEN MULTIPLE ARCH DAM Filed Aug. 8. 1927 2 Sheets-Sheet 2 Pd/lr Nnmwh Patented July 12, 1932 v unite srares RUDOLPH w. VAN NOBIDEN, or sen FRANCISCO, 'ennu 01m n P1 T E MULTIPLE ARCH DAM Application filed August 8, 1927. Serial 'No. 211,337. a

I My invention relates to structures for damming streams and rivers and is particularly related to a novel form of dam comprising a plurality of arches. "An object of my invention is to provide a dam which requires material. l

Another object of my invention is to provide a dam in which the stresses are transmittedto the foundation in an efficient manner. V v

My invention possesses other advantageous features, some of which with the foregoing will be set, forth at length in the following description where I shall outline in full that form of the multiple arch dam of my invention, whichI have selected for illustration in the drawings accompanying and forming part of the present specification. In said drawingsI have shown one form of'multiple arch dam embodying my invention, but it is to be understood that I do not limit myself i to such form since the invention, as set forth in the claims, may be embodied in a plurality of forms.

In the drawings:

Fig. 1 is aplan of one form of dam of my invention.

Fig. 2 is a cross section of the dam shown in Fig. 1, the planerof section being indicated by line 2-2. V

Fig. 3 is a plan of a modified form of dam of my invention.

Fig. i is a cross-section on the line 4 1 of Fig. 3.

Fig. 5 is a plan of another modified form of my dam.

Fig. 6 is a cross section on the line 66 of Fig. 5.

Fig. 7 is a horizontal section on the line 7--7 of Fig. 8 of a' variant form of dam of my invention;

Fig. 8 is a cross section-of the dam disclosed in Fig. 7, the plane of section being indicated by line 88 of Fig. 7

In its preferred form, the vention preferably comprises a plurality of conoidal shells or arches arranged in juxtaposition with their axes substantially intersecting.

but a small amount ofdam of my in-.

There are various ways offbuilding a dam according to myinventionfand I disclose herein. In each instance, the dam comprises (a plurality of arches or shells, each of which is a portion of a cone. Thecone on whichthearch is some of these various .ways' constructed can be either 0 ircular. or ship:

soidal and any portion of; a' conical surface can be utillzed. As shown in Fig.1, the dam comprises a central conical arch or shell 6' extending substantially across the walls 7 and 8 of the canyon in which the dam is situated.

At either side of the central shell 6; areside shells9 and 11 alsoof conoidal contour and preferably arranged with the cone elements parallel to the cone elements of the central shell at the springinglines of the arches. In this manner the axes oftheconoidal sur faces converge. j The shells,,6',' 9, and- 11;. are

supported bv; buttresses 1'2 and extend in 7 and 80f the canyon.

an mm the .buttresses as their bases extend upithe walls of the canyon. 1, Advantage is taken of the slope of the canyon Walls 7 and 8so that the terminations ofthe heel portions of the buttresses are considerably. above the toe portions..' Not'only is there ,a firm support providedfor the dam by the. canyon walls but a large amount of material "and labor is.

in constructing the buttresses A further ad- .vanta that t uniformly from c of theconoidal shell construction is e radius of the arch surface decreases the top toward the bottom ofthe arch. Since the thickness of the arch pressure and the at any point is determined by the hydraulic arch radius} at that point i originate'at the sprlnging llnes of the arches j diverging lanes to theLw'alls the decreasing radius toward the bottomof the shell counteracts in a measure the increas ing hydraulic 'pressure with the depth and consequently permits a relatiirelythin arch section ,to be used.

In Fig. 3 is dis what straighter and 17 than the I this instance jthe' decrease i closed a jsomewhat modified j form of dam in which the 'dame'xtendssomeacross theic'anyon walls. 16 dam shown in Fig. .11. p In 'n' radiu's of the conoidal surface toward the bottomof the dam is taken advantage, of to lessen the necessary dimensions of the arch ring. In addi tion,the various conoidal shells 18, 19 and 20 comprising the dam are arranged in such relationship that the angle subtended by any particular horizontal section or any section normal to the axis ofthe central arch varies with the height of the arch. The angles subtended by the conoidal surface exposed in the central arch 19 at various elevations taken along the conoidal axis are indicated on the figure. 7 It will be seen that the subtended angles decrease considerably toward the top" of-the arch. This decrease is nota constant amount but varies with the height. Adjacent the contact of the arch 19 with-the ground in the canyon,

V the subtended angles vary but little, while as "thearc'h leaves the ground and extends up- Wardly, the subtended angles at successive elevations become less. Inasmuch as the sub tended angle' included within the sides of each shell is increased as the'bottom of the shell ,is approached, considerable material can be saved in the construction of theshells inasmuch as the maximum fiber stresses in the material decrease'with an increased subtion and so that theyfpro-vid-e a firmlsupport ji fiorthe'dam. A somewhat similar'form of dam is dis closed-in Figs; 5 and G-inwhich the conoidal and are'supporte'd bydrvergi'ng buttresses 27 shells 23; 4' and 25 are arranged-with their elements non-parallel at the springin g lines and 28'. Injthi's instance the angles'subtended by the springing lines of the central shell 24: vary considerably between the lowermost portion and the top of the shell. Arch rings taken at equal intervals thruout the height lot the shell and either in horizontal planes or'in planes normal to the axis of the conoidal surface disclose that'the subtended angles increase somewhat until the central shell --'intersect's the forward faces 29 and 31 ot-it'he buttresses 27 and 28, thence remaining substantially .con'stant until the S rfaces oft-he shells 23,1 2st and 25 intersectl, These intersectin surfaces are mathematically parabolas' in practice are so nearly straight lines that they can" be considerediassuch 7 herein. vThe; intersecting surfac'esfcau'sethe angles subtended by the upper-portions of the arch 24. to decrease atfa constant rateuntil they are. approximatel y of the same value .a-t thetop asthey are attheverybottom; V V -r The form of dam: d sclosed inFigs. (and 8. is fundamentally ,the same imis'inucfli as it s includes a central arch 32 and flanking arches rality of conoidal shells'in 33 and 34,-all'of which are conoidal surfaces arranged in order across a canyon. The

conoidal shells are supported by buttresses 36 and 37 diverging in the usual manner but the feature ofthis modification is' that the forward faces of the buttresses 36 and 37 are in themselves supplementary conoidal shells 38 and 39 which intersect the shells 32, 33 and 34'. Inasmuch as the pressure is distributed by the supplemental arches 38 and 39, the interior of the buttresses36 and 37 can be made hollow and a saving in material is thereby effected. V I p 'In'all forms o'ii'thedam of my invention, the arches or shell sections are conoidal in buttresses diverge; This construction perform and are arranged so that the supporting mits the use of considerably less material in forming the arches and in forming the but-- tresses and provides at a less cost a dam equal in" strength and stabilitytothose in use.

I claim:

of the dam, and supplementary conoidal shells in abutment with said first named shells i 1. A multiple arch comprising a p111 andhaving theinap'icestowardthetop of the dam. r 2. A multiple arch dam comprising apl'uternate shellsjbeing inverted. N v p I 3. A multiplexarch dam comprising apierality of ialte conoidal shells injuxtapositionq I rnately-"uprjight and inverted uxtaposition, al-.

4. A multiple archdam' comprisinga plu- .rality o'f substantially upright and inverted l conoidal shells in juxtaposition.

In testimony whereof, I have hereunto set myhand. RUDOLPH W. VAN NQRDEN.

ion. 

